Psychiatrists are adopting a novel approach to uncover the causes of bipolar depression, with the illness now being viewed not just as a mood disorder but as a metabolic disturbance that can be addressed through dietary and other interventions aimed at altering bodily processes.

One promising area of research is the development of metabolic treatments to manage manic and depressive episodes. “Developing metabolic treatments could help curb bouts of mania and lethargic depression,” a researcher at Edinburgh University, Iain Campbell, told the Guardian.

“Ketogenic diets, in which a person eats no carbohydrates but lots of fats, are quite common,” he said. “They are used to cut weight but also to treat epilepsy in some cases. However, it is now becoming clear they can help alleviate bipolar depression.”

A recent study at Edinburgh University examined the effects of a ketogenic diet on 27 individuals with bipolar depression over eight weeks. A third of the participants were more stable and less impulsive.

Researchers are also examining seasonal patterns in bipolar depression. Many individuals experience heightened depressive episodes in autumn and winter, while manic phases increase in spring and autumn.

“We should be thinking of bipolar depression, not as a primary emotional problem, but as a malfunctioning of energy regulation in the body,” Mr. Campbell, who helped set up Edinburgh University’s new Hub for Metabolic Psychiatry, said. “It is a very different way of thinking about mental illness.”